Sound-box.



No. 764,868. PATENTED JULY 12', 1904. 'G. ROBERTSON SOUND BOX.

APPLIGATION FILED 13110.1. 1903.

NO MODEL.

flu van foz Patented July 12, 1904.

PATENT OFFICE.

UNITED STATES GEORGE ROBERTSON, OF TOLEDO, OHIO.

SOUND-BOX.

SPECIFICATION forming part of Letters Patent No. 764,868, dated July 12,1904.

Application filed. December 1, 1903- Serial No. 183,337. (No model.)

useful Improvements in Sound-Boxes; and I do hereby declare thefollowing to be a full,

'clear, and exact description of the invention,

such as will enable others skilled in the art to which it pertains tomake and use the same.

This invention relates to sound-boxes for disk talking-machines, andparticularly to the supporting means for the needle-arm, the objectbeing to improve and simplify such means.

In the accompanying drawings, Figures 1 and 2 are side views at rightangles to each other of a sound-box having the improvements. Fig. 3 isan enlarged side view of a modification of the bearing for theneedlearm. Fig. 4 is a front view of the sound-box, and Fig. 5 is apartial sectional view on line 5 5 of Fig. 3 on an enlarged scale.

Numeral 1 denotes the sound-box body, 2 the diaphragm, and 3 theneedle-arm. This arm is connected to the center of the diaphragm andextends radially beyond the periphery of the box, where it is supportedby a tension-spring 4 and screw or pin 4, which screw or pin is heldloosely in a hole in the projection 5 of box 1, and the projection iseither integral or non-integral with the box, preferably the former, asit is safer. In said hole is the spiral tension-spring which pressesagainst the head of the screw and against a ledge 4 in the hole. Thusthe screw (and hence the needle-arm) is supported by the tension of saidspring.

Just outside of the box needle-arm 3 is provided with side wings orhearing parts 6 6, the smooth fiat inner side of which rests on the hardsmooth rounded parts, preferably polished steel balls 7 which are indepressions in the extension or which are in sockets 5", screwed intoholes in part 5. The balls are held securely in place by overlyingmaterial extending outward beyond the centers of the balls, so as tohold the balls from falling out when they are not under wings 6. Theballs may thus be held stationary or they may be sufficiently loose intheir sockets to allow them to turn.

The screw or pin 4 draws the wings 6 of the needle-bar against balls 7WVhen arm 3 is vibrated by a record, wings 6 move slightly on the roundparts 7 where said parts touch. Evidently the balls may be fixed towings 6 instead of to part 5. The balls can bear directly against theflat inner side of wings 6 without the formation of special bearingplaces. The balls wear the opposing surface so little as to benegligible. The reproducer is therefore not interfered with.

It will be seen that there is but one tensionscrew used and that but oneis necessary, owing partly to the cooperating action of the wings andballs.

I have shown, Fig. 4:, the screw 4 located below the centers of balls 7;but this is not essential. The action is, however, better when saidscrew is at one side or the other of a line through the center of theballs.

In order to lower the arm 3 to a plane quite near to the plane of thediaphragm, a notch 3 for said arm is formed in the outer edge of thesound-box. In this way arm 3 is brought .down nearly to the wire ring 2,which holds the diaphragm.

WVhat I claim is- 1. A talking-machine sound-box having a suitable case,diaphragm, and a needle-arm operatively connected at one end to thediaphragm, a single screw adjustably supported in the needle arm andextending loosely through an extension from the box, a spring betweenthe extension and the head of the screw, the rounded bearing againstwhich the arm presses normally, said screw engaging the arm at a pointat one side of a plane transverse to the arm and passing through thecenter of the rounded bearing, whereby adjustment of said screw changesthe tension of the arm on the diaphragm.

2. A talking-machine sound-box having a suitable case, diaphragm, andneedle arm, means for securing said arm outside of the case consistingof a projecting part 5, and a single screw extending therethrough intosaid arm, and balls on opposite sides of the axis of said needle-armagainst which the arm bears and on which it can move.

3. A talking-machine sound-box having a suitable case, diaphragm,needle-armwith opposite side wings, a single screw for securing saidarm, and balls on opposite sides of the axis of the needle-arm againstwhich said wings bear and on which they can move.

4. A talking-machine sound-box having a case, diaphragm, and needle arm,a single screw for securing said arm, and balls on opposite sides of theaxis of said needle-arm against which the arm bears on opposite sides ofsaid axis of the needle-arm and also at one side of a plane transverseto the needle-arm and passing through the axis of the screw.

5. A talking-machine sound-b0x having a suitable case, diaphragm, andneedle-arm, a notch in the case for the arm, a part 5 projecting fromthe case at the rear of said notch, and means in part 5 supporting thearm.

6. A sound-box case having a projecting .and balls forming a bearing forthe needlearm.

In testimony whereof I have signed this specification in the presence oftwo subscrib- 3 ing witnesses.

GEORGE ROBERTSON.

Witnesses:

CLEM V. WAGNER, L. M. VVILLIAMsoN.

